POLICY FOR TREATMENT OF CENTRAL NERVOUS SYSTEM INFECTIONS IN ADULTS

Transcription

1 POLICY FOR TREATMENT OF CENTRAL NERVOUS SYSTEM INFECTIONS IN ADULTS Written by: Dr M Milupi, Consultant Microbiologist Dr B Subramanian, Specialist Registrar Date: February 2016 Approved by: Drugs & Therapeutics Committee Date: July 2016 Implementation Date: August 2016 For Review: July 2018 This document is part of antibiotic formulary guidance Formulary guidance holds the same status as Trust policy

2 Contents 1) Meningitis a.definition i. Bacterial Meningitis Investigations ii. Viral Meningitis Investigations 2) Meningococcal septicaemia a. Definition b. Investigations c. 3) Encephalitis a. Definition b. Investigations c.

3 1) Meningitis Definition Inflammation of the meninges may be bacterial, viral or aseptic meningitis. The classic triad of fever, neck stiffness and altered mental status (GCS 14) is not always present. May have signs specific to the infecting organism e.g. purpuric rash in meningococcal meningitis. In culture-proven bacterial meningitis: 95% of patients have 2 of the following symptoms and signs 99% of patients have at least 1 Headache Fever Neck stiffness Altered mental state Viral meningitis is thought to account for about 50 80% of all cases of meningitis. (i) Bacterial meningitis Common causative organisms Neisseria meningitidis Haemophilus influenzae, type B Streptococcus pneumoniae Listeria monocytogenes (especially in immunocompromised, pregnant or diabetic patients) M.tuberculosis Cryptococcus Blood culture CSF for microscopy, culture &sensitivity EDTA blood Meningocococal & Pneumococcal PCR(after discussion with Microbiologist) Bacterial throat swab Ensure LP is done within the 1 st hour of admission to hospital but note that LP can still be useful for up to 3 days after antibiotics have been started 1 st line Penicillin anaphylaxis Duration Adults < 60 years Adults 60 years Immunocompromis ed, diabetes or alcohol excess Cefotaxime (IV) 2g 6-hourly Cefotaxime (IV) 2g 6-hourly AND Amoxicillin (IV) 2g 4-hourly OR( if rash to Penicilin) Co-trimoxazole (IV) 15mg/kg 6-hourly (double the dose in severe infections) Chloramphenicol (IV) 25mg/kg 6-hourly Chloramphenicol (IV) 25mg/kg 6-hourly AND Co-trimoxazole (IV) 15mg/kg 6-hourly (double the dose in severe infections) Meningococcal 7 days Pneumococcal days Haemophilus influenzae 10 days Listeria 21 days

4 Steroids Dexamethasone (IV) 10mg 6-hourly should be administered for ALL cases of suspected bacterial meningitis: This should be started on admission, either shortly before or simultaneously with antibiotics. Can start dexamethasone up until 12 hours after the first dose of antibiotics. If pneumococcal meningitis is confirmed, or thought likely based on clinical, epidemiological and CSF parameters, dexamethasone should be continued for 4 days. If another cause of meningitis is confirmed, or thought likely, the dexamethasone should be stopped (ii) Viral Meningitis Common causative organisms Herpes simplex virus(hsv)-usually HSV-2 Varicella Zoster virus(vzv) Enterovirus As the initial clinical presentation for bacterial and viral meningitis are similar, initial investigations will be the same (see notes above Bacterial meningitis ). Plus CSF for HSV, VZV and Enterovirus PCRs For any additional viral PCR, please discuss with the Virologist(based at the Northern General Hospital, Sheffield) or Microbiologist Currently there are no antiviral treatments of proven benefit for viral meningitis. However, identifying a viral cause allows the patient to be given a diagnosis and for antibiotics to be stopped. is largely supportive eg antipyretics, analgesics

5 2) Meningococcal septicaemia Definition Evidence of sepsis +/- characteristic petechial/purpuric skin rash and hypoperfusion. Neisseria meningitidis may be identified from blood, CSF or skin lesions. Patients with meningococcal septicaemia can deteriorate rapidly. The classic petechial or purpuric rash occurs in 60%, but this can be a late sign. Certain symptoms that should raise alarm are severe muscle pain (a possible feature of systemic bacterial sepsis) or thirst (a prominent feature of impending shock even when the blood pressure is normal). Temperature may be high, low or normal. Common causative organism Neisseria meningitidis Blood cultures Meningococcal and pneumococcal PCR (1 x EDTA tube to microbiology) Throat swab for mc&s LP should NOT be performed in these patients. 1 st line Penicillin anaphylaxis Duration Cefotaxime (IV) 2g 6- hourly Chloramphenicol (IV) 25mg/kg 6-hourly 7 days 4) Encephalitis Definition Inflammation of the brain substance. Involvement of particular areas of the brain can occur with specific pathogens. Usually presents with headache, fever, change in cognitive state (e.g. confusion, personality change). Focal features, such as reduced GCS or seizures, may occur.

6 The most frequent cause of encephalitis in the UK is HSV-1. It tends to affect the temporal and/or frontal lobes. Bacterial, parasitic and fungal cause are rare in the UK. Common causative organisms Herpes simplex(hsv)-usually HSV-1 Varicella Zoster virus(vzv) CSF for viral PCR AND microscopy culture & sensitivities Blood culture Note: CT head, MRI brain or EEG should be performed to confirm the diagnosis Prompt treatment should be initiated. Treating early in the course of the illness before the development of haemorrhagic necrosis is critical to improve neurological outcome. 1 st line 2 nd line Duration Aciclovir 10mg/kg 8-hourly (IV) Contact the Virologist (based at Northern General Hospital )or the Microbiologist 21 days If there remains a strong clinical suspicion of viral encephalitis despite negative CSF viral PCR, discuss with the Virologist (based at Northern General Hospital ) or the Microbiologist for further advice. References Association of British Neurologists and British Infection Association National Guidelines. Management of suspected viral encephalitis in adults. Journal of Infection 2012 Apr; 64(4): British Infection Association: Early management of suspected bacterial meningitis and meningococcal septicaemia in immunocompetent adults. Journal of Infection

7 2003; 46: Infectious Diseases Society of America: Practice guideline for the management of bacterial meningitis (CID) 2004; 39: Patient_Care/PDF_Library/Bacterial%20Meningitis%281%29.pdf McGill F, et al., The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults, J Infect (2016), van de Beek D, de Gans J, Spanjaard L, Weisfelt M, Reitsma JB, Vermeulen M. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med 2004 Oct; 351(18):